Greasing a B21 BH Pivot

[joea99]

While pondering what to do about a bent "thumb" (steel one), I noticed two grease point I don't recall every touching before today. The are the two on the BH pivot, which seem quite difficult to get a straight shot at as the boom seem to leave very little clearance.

I have a lock n lube coupler, extended version. Thinking of getting the shorter version as well, or maybe just getting some right angle zerks and putting them in. That is cheaper, of course, but every time I buy zerks, the seem wrong and I end up with "too many zerks". Probably I have no Right Angle ones in the last "universal" kit I bought.

Who knows the right size an who has them?

 

[Smokeydog]

I swing the boom to the side to access those zerks. Same for the swing cylinders grease points.

 

[number two]

I swing the boom to the side to access those zerks. Same for the swing cylinders grease points.

If you still want to change the zerks,they are most likely 1/4 x 28NF.
If a little larger,then 1/8 NPT would work.
Good Luck!

 

[Smokeydog]

Kubotas have been a mixed bag of different threads for grease zerks. Have good selection of assorted English and metric. Most tend to be British and frustrating. Small ones will cross with English but bigger ones will not. Hard to find a British thread assortment priced reasonably. Just buy a couple extra from the Kubota dealer. Running good grease rarely have plugging problems.

 

[rScotty]

I believe the zerks you are describing are swing pivot bushings. Right on center at the bottom of the BH? That is a Very High Stress area, so you need to get some grease in there. That's one of the few places on the TLB where I will use the dreaded moly grease.

Our M59 has at least three different zerk threads, and it's a guessing game to tell which one is a fit. Even worse, the threads are short, often buggered to start, and easily cross threaded.

Someday I am going to get a "Grease Zerk Thread Gauge". Zoro.com has what looks to be a nice one for under thirty bucks. It identifies twenty some odd different zerk threads & is made in the USA....maybe.

They also sell a plastic one from India that is more expensive. You gotta wonder why?

 

[Smokeydog]

I believe the zerks you are describing are swing pivot bushings. Right on center at the bottom of the BH? That is a Very High Stress area, so you need to get some grease in there. That's one of the few places on the TLB where I will use the dreaded moly grease.

Our M59 has at least three different zerk threads, and it's a guessing game to tell which one is a fit. Even worse, the threads are short, often buggered to start, and easily cross threaded.

Someday I am going to get a "Grease Zerk Thread Gauge". Zoro.com has what looks to be a nice one for under thirty bucks. It identifies twenty some odd different zerk threads & is made in the USA....maybe.

They also sell a plastic one from India that is more expensive. You gotta wonder why?View attachment 712124

Didn’t know there are three different thread type grease types on the M59 backhoe. I thought all Kubota loaders and backhoe are made in the states? Maybe globally sourced parts?

Might need to make my own zerk thread tester from some fittings. Might be a new tool opportunity for us orange folk.

 

[number two]

Since the most of the Kubota attachments are North American,I figure the zerks are fractional.
The Canadian snowblowers seem to be fractional as well.
The tractors are of Asian manufacture-I figure their fittings are metric.
YMMV

 

[rScotty]

Since the most of the Kubota attachments are North American,I figure the zerks are fractional.
The Canadian snowblowers seem to be fractional as well.
The tractors are of Asian manufacture-I figure their fittings are metric.
YMMV

Uh.... you may want to check your figuring on that.
The problem is that Zerks use tapered threads - and tapered self-sealing threads are a whole different thread world off by itself.

Hardly anyone uses the metric tapered thread. Yes, there is a metric tapered thread standard, but about the only place you see it used is for some - you guessed it - special zerks. For most fluid tight joints and zerks, Asian manufacturers usually prefer to use one of the British Tapered Pipe Standards. That goes for most things Asian requiring an self-sealing interference type of thread. And includes many Asian-made zerks plus most all hose and sensor fittings on Asian cast engine blocks.

Most - not all - North American manufacturers do use NTP for their zerks. But some use an oddball thread per inch spec.

Zerk specs really don't make sense. Measuring each zerk against a thread gauge is the only way to be sure.

 

[Smokeydog]

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[number two]

Uh.... you may want to check your figuring on that.
The problem is that Zerks use tapered threads - and tapered self-sealing threads are a whole different thread world off by itself.

Hardly anyone uses the metric tapered thread. Yes, there is a metric tapered thread standard, but about the only place you see it used is for some - you guessed it - special zerks. For most fluid tight joints and zerks, Asian manufacturers usually prefer to use one of the British Tapered Pipe Standards. That goes for most things Asian requiring an self-sealing interference type of thread. And includes many Asian-made zerks plus most all hose and sensor fittings on Asian cast engine blocks.

Most - not all - North American manufacturers do use NTP for their zerks. But some use an oddball thread per inch spec.

Zerk specs really don't make sense. Measuring each zerk against a thread gauge is the only way to be sure.

I apologize for my incorrect figuring!
I'm so used to seeing British Standard Pipe on the vast majority of imports,that I kind of think of them as metric.
The thread checker looks cool!